sup everyone. i have a 2003 black g35 coupe. i have the JWT intake, crawford plenum, test pipes, and apexi n-1 exhaust. the car runs fine however, ever since i installed the plenum, the car seems to run rich. when i rev the motor and or just let it idle, i can smell gas fumes from the exhaust... anyone have any theores???? thanks everyone!!

 

i had the same thing happen when i install the HKS exhasut..

i get backfire too.

 

I had the samething happen after I installed test pipes and it got worse after I put on the Kinetix plenum. It has been like that for almost 2 years and I haven't seen any negitive effects.
Brian

 

could always get it tuned to the correct a/f ratio

 

Can't tune a stock ECU, I'm waiting for the Cobb Tuning setup to become available. Should be sometime this summer.
Brian

 

It's not running rich. It's because you don't have the pre-cats on anymore and it's not cleaning up the exhaust as much as before. If anything, you would be running lean.

 

I wouldn't say you are running rich. If anything you would be running lean. Your car is just breathing better, which is why you are getting the different smell. You can definitely smell the difference when you are running your car in your garage with just a CAI.

 

Haha. I think you spent too much time doing that

 

+1. Your car is just breathing better, which is why you are getting the different smell. You can definitely smell the difference when you are running your car in your garage with just a CAI.

 

1) The car won't breath any "better" with just the cai.
2) The reason the smell is diff is the elimation of the precats. Not because of any breathing improvents (although the test pipes WOULD actually do this). If you put test pipes in that had a restrictor (so it would "breath" the same as before), you would still get that diff smell.